/* Indentation functions. Copyright (C) 1985,86,87,88,93,94,95 Free Software Foundation, Inc.This file is part of GNU Emacs.GNU Emacs is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2, or (at your option)any later version.GNU Emacs is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Emacs; see the file COPYING. If not, write tothe Free Software Foundation, Inc., 59 Temple Place - Suite 330,Boston, MA 02111-1307, USA. */#include <config.h>#include "lisp.h"#include "buffer.h"#include "indent.h"#include "frame.h"#include "window.h"#include "termchar.h"#include "termopts.h"#include "disptab.h"#include "intervals.h"#include "region-cache.h"/* Indentation can insert tabs if this is non-zero; otherwise always uses spaces */intindent_tabs_mode;#define min(a, b) ((a) < (b) ? (a) : (b))#define max(a, b) ((a) > (b) ? (a) : (b))#define CR 015/* These three values memoize the current column to avoid recalculation *//* Some things in set last_known_column_point to -1 to mark the memoized value as invalid *//* Last value returned by current_column */intlast_known_column;/* Value of point when current_column was called */intlast_known_column_point;/* Value of MODIFF when current_column was called */intlast_known_column_modified;staticintcurrent_column_1();/* Get the display table to use for the current buffer. */structLisp_Char_Table*buffer_display_table(){Lisp_Objectthisbuf;thisbuf=current_buffer->display_table;if(DISP_TABLE_P(thisbuf))returnXCHAR_TABLE(thisbuf);if(DISP_TABLE_P(Vstandard_display_table))returnXCHAR_TABLE(Vstandard_display_table);return0;}/* Width run cache considerations. *//* Return the width of character C under display table DP. */staticintcharacter_width(c,dp)intc;structLisp_Char_Table*dp;{Lisp_Objectelt;/* These width computations were determined by examining the cases in display_text_line. *//* Everything can be handled by the display table, if it's present and the element is right. */if(dp&&(elt=DISP_CHAR_VECTOR(dp,c),VECTORP(elt)))returnXVECTOR(elt)->size;/* Some characters are special. */if(c=='\n'||c=='\t'||c=='\015')return0;/* Printing characters have width 1. */elseif(c>=040&&c<0177)return1;/* Everybody else (control characters, metacharacters) has other widths. We could return their actual widths here, but they depend on things like ctl_arrow and crud like that, and they're not very common at all. So we'll just claim we don't know their widths. */elsereturn0;}/* Return true iff the display table DISPTAB specifies the same widths for characters as WIDTHTAB. We use this to decide when to invalidate the buffer's width_run_cache. */intdisptab_matches_widthtab(disptab,widthtab)structLisp_Char_Table*disptab;structLisp_Vector*widthtab;{inti;if(widthtab->size!=256)abort();for(i=0;i<256;i++)if(character_width(i,disptab)!=XFASTINT(widthtab->contents[i]))return0;return1;}/* Recompute BUF's width table, using the display table DISPTAB. */voidrecompute_width_table(buf,disptab)structbuffer*buf;structLisp_Char_Table*disptab;{inti;structLisp_Vector*widthtab;if(!VECTORP(buf->width_table))buf->width_table=Fmake_vector(make_number(256),make_number(0));widthtab=XVECTOR(buf->width_table);if(widthtab->size!=256)abort();for(i=0;i<256;i++)XSETFASTINT(widthtab->contents[i],character_width(i,disptab));}/* Allocate or free the width run cache, as requested by the current state of current_buffer's cache_long_line_scans variable. */staticvoidwidth_run_cache_on_off(){if(NILP(current_buffer->cache_long_line_scans)){/* It should be off. */if(current_buffer->width_run_cache){free_region_cache(current_buffer->width_run_cache);current_buffer->width_run_cache=0;current_buffer->width_table=Qnil;}}else{/* It should be on. */if(current_buffer->width_run_cache==0){current_buffer->width_run_cache=new_region_cache();recompute_width_table(current_buffer,buffer_display_table());}}}/* Skip some invisible characters starting from POS. This includes characters invisible because of text properties and characters invisible because of overlays. If position POS is followed by invisible characters, skip some of them and return the position after them. Otherwise return POS itself. Set *NEXT_BOUNDARY_P to the next position at which it will be necessary to call this function again. Don't scan past TO, and don't set *NEXT_BOUNDARY_P to a value greater than TO. If WINDOW is non-nil, and this buffer is displayed in WINDOW, take account of overlays that apply only in WINDOW. We don't necessarily skip all the invisible characters after POS because that could take a long time. We skip a reasonable number which can be skipped quickly. If there might be more invisible characters immediately following, then *NEXT_BOUNDARY_P will equal the return value. */staticintskip_invisible(pos,next_boundary_p,to,window)intpos;int*next_boundary_p;intto;Lisp_Objectwindow;{Lisp_Objectprop,position,end,overlay_limit,proplimit;Lisp_Objectbuffer;XSETFASTINT(position,pos);XSETBUFFER(buffer,current_buffer);/* Give faster response for overlay lookup near POS. */recenter_overlay_lists(current_buffer,pos);/* We must not advance farther than the next overlay change. The overlay change might change the invisible property; or there might be overlay strings to be displayed there. */overlay_limit=Fnext_overlay_change(position);/* As for text properties, this gives a lower bound for where the invisible text property could change. */proplimit=Fnext_property_change(position,buffer,Qt);if(XFASTINT(overlay_limit)<XFASTINT(proplimit))proplimit=overlay_limit;/* PROPLIMIT is now a lower bound for the next change in invisible status. If that is plenty far away, use that lower bound. */if(XFASTINT(proplimit)>pos+100||XFASTINT(proplimit)>=to)*next_boundary_p=XFASTINT(proplimit);/* Otherwise, scan for the next `invisible' property change. */else{/* Don't scan terribly far. */XSETFASTINT(proplimit,min(pos+100,to));/* No matter what. don't go past next overlay change. */if(XFASTINT(overlay_limit)<XFASTINT(proplimit))proplimit=overlay_limit;end=Fnext_single_property_change(position,Qinvisible,buffer,proplimit);*next_boundary_p=XFASTINT(end);}/* if the `invisible' property is set, we can skip to the next property change */if(!NILP(window)&&EQ(XWINDOW(window)->buffer,buffer))prop=Fget_char_property(position,Qinvisible,window);elseprop=Fget_char_property(position,Qinvisible,buffer);if(TEXT_PROP_MEANS_INVISIBLE(prop))return*next_boundary_p;returnpos;}DEFUN("current-column",Fcurrent_column,Scurrent_column,0,0,0,"Return the horizontal position of point. Beginning of line is column 0.\n\This is calculated by adding together the widths of all the displayed\n\representations of the character between the start of the previous line\n\and point. (eg control characters will have a width of 2 or 4, tabs\n\will have a variable width)\n\Ignores finite width of frame, which means that this function may return\n\values greater than (frame-width).\n\Whether the line is visible (if `selective-display' is t) has no effect;\n\however, ^M is treated as end of line when `selective-display' is t.")(){Lisp_Objecttemp;XSETFASTINT(temp,current_column());returntemp;}/* Cancel any recorded value of the horizontal position. */invalidate_current_column(){last_known_column_point=0;}intcurrent_column(){registerintcol;registerunsignedchar*ptr,*stop;registerinttab_seen;intpost_tab;registerintc;registerinttab_width=XINT(current_buffer->tab_width);intctl_arrow=!NILP(current_buffer->ctl_arrow);registerstructLisp_Char_Table*dp=buffer_display_table();intstopchar;if(PT==last_known_column_point&&MODIFF==last_known_column_modified)returnlast_known_column;/* If the buffer has overlays or text properties, use a more general algorithm. */if(BUF_INTERVALS(current_buffer)||!NILP(current_buffer->overlays_before)||!NILP(current_buffer->overlays_after))returncurrent_column_1(PT);/* Scan backwards from point to the previous newline, counting width. Tab characters are the only complicated case. *//* Make a pointer for decrementing through the chars before point. */ptr=&FETCH_CHAR(PT-1)+1;/* Make a pointer to where consecutive chars leave off, going backwards from point. */if(PT==BEGV)stop=ptr;elseif(PT<=GPT||BEGV>GPT)stop=BEGV_ADDR;elsestop=GAP_END_ADDR;if(tab_width<=0||tab_width>1000)tab_width=8;col=0,tab_seen=0,post_tab=0;while(1){if(ptr==stop){/* We stopped either for the beginning of the buffer or for the gap. */if(ptr==BEGV_ADDR)break;/* It was the gap. Jump back over it. */stop=BEGV_ADDR;ptr=GPT_ADDR;/* Check whether that brings us to beginning of buffer. */if(BEGV>=GPT)break;}c=*--ptr;if(dp!=0&&VECTORP(DISP_CHAR_VECTOR(dp,c)))col+=XVECTOR(DISP_CHAR_VECTOR(dp,c))->size;elseif(c>=040&&c<0177)col++;elseif(c=='\n')break;elseif(c=='\r'&&EQ(current_buffer->selective_display,Qt))break;elseif(c=='\t'){if(tab_seen)col=((col+tab_width)/tab_width)*tab_width;post_tab+=col;col=0;tab_seen=1;}elsecol+=(ctl_arrow&&c<0200)?2:4;}if(tab_seen){col=((col+tab_width)/tab_width)*tab_width;col+=post_tab;}last_known_column=col;last_known_column_point=PT;last_known_column_modified=MODIFF;returncol;}/* Return the column number of position POS by scanning forward from the beginning of the line. This function handles characters that are invisible due to text properties or overlays. */staticintcurrent_column_1(pos)intpos;{registerinttab_width=XINT(current_buffer->tab_width);registerintctl_arrow=!NILP(current_buffer->ctl_arrow);registerstructLisp_Char_Table*dp=buffer_display_table();/* Start the scan at the beginning of this line with column number 0. */registerintcol=0;intscan=find_next_newline(pos,-1);intnext_boundary=scan;if(tab_width<=0||tab_width>1000)tab_width=8;/* Scan forward to the target position. */while(scan<pos){intc;/* Occasionally we may need to skip invisible text. */while(scan==next_boundary){/* This updates NEXT_BOUNDARY to the next place where we might need to skip more invisible text. */scan=skip_invisible(scan,&next_boundary,pos,Qnil);if(scan>=pos)gotoendloop;}c=FETCH_CHAR(scan);if(dp!=0&&VECTORP(DISP_CHAR_VECTOR(dp,c))){col+=XVECTOR(DISP_CHAR_VECTOR(dp,c))->size;scan++;continue;}if(c=='\n')break;if(c=='\r'&&EQ(current_buffer->selective_display,Qt))break;scan++;if(c=='\t'){intprev_col=col;col+=tab_width;col=col/tab_width*tab_width;}elseif(ctl_arrow&&(c<040||c==0177))col+=2;elseif(c<040||c>=0177)col+=4;elsecol++;}endloop:last_known_column=col;last_known_column_point=PT;last_known_column_modified=MODIFF;returncol;}/* Return the width in columns of the part of STRING from BEG to END. If BEG is nil, that stands for the beginning of STRING. If END is nil, that stands for the end of STRING. */staticintstring_display_width(string,beg,end)Lisp_Objectstring,beg,end;{registerintcol;registerunsignedchar*ptr,*stop;registerinttab_seen;intpost_tab;registerintc;registerinttab_width=XINT(current_buffer->tab_width);intctl_arrow=!NILP(current_buffer->ctl_arrow);registerstructLisp_Char_Table*dp=buffer_display_table();intb,e;if(NILP(end))e=XSTRING(string)->size;else{CHECK_NUMBER(end,0);e=XINT(end);}if(NILP(beg))b=0;else{CHECK_NUMBER(beg,0);b=XINT(beg);}/* Make a pointer for decrementing through the chars before point. */ptr=XSTRING(string)->data+e;/* Make a pointer to where consecutive chars leave off, going backwards from point. */stop=XSTRING(string)->data+b;if(tab_width<=0||tab_width>1000)tab_width=8;col=0,tab_seen=0,post_tab=0;while(1){if(ptr==stop)break;c=*--ptr;if(dp!=0&&VECTORP(DISP_CHAR_VECTOR(dp,c)))col+=XVECTOR(DISP_CHAR_VECTOR(dp,c))->size;elseif(c>=040&&c<0177)col++;elseif(c=='\n')break;elseif(c=='\t'){if(tab_seen)col=((col+tab_width)/tab_width)*tab_width;post_tab+=col;col=0;tab_seen=1;}elsecol+=(ctl_arrow&&c<0200)?2:4;}if(tab_seen){col=((col+tab_width)/tab_width)*tab_width;col+=post_tab;}returncol;}DEFUN("indent-to",Findent_to,Sindent_to,1,2,"NIndent to column: ","Indent from point with tabs and spaces until COLUMN is reached.\n\Optional second argument MININUM says always do at least MININUM spaces\n\even if that goes past COLUMN; by default, MININUM is zero.")(column,minimum)Lisp_Objectcolumn,minimum;{intmincol;registerintfromcol;registerinttab_width=XINT(current_buffer->tab_width);CHECK_NUMBER(column,0);if(NILP(minimum))XSETFASTINT(minimum,0);CHECK_NUMBER(minimum,1);fromcol=current_column();mincol=fromcol+XINT(minimum);if(mincol<XINT(column))mincol=XINT(column);if(fromcol==mincol)returnmake_number(mincol);if(tab_width<=0||tab_width>1000)tab_width=8;if(indent_tabs_mode){Lisp_Objectn;XSETFASTINT(n,mincol/tab_width-fromcol/tab_width);if(XFASTINT(n)!=0){Finsert_char(make_number('\t'),n,Qt);fromcol=(mincol/tab_width)*tab_width;}}XSETFASTINT(column,mincol-fromcol);Finsert_char(make_number(' '),column,Qt);last_known_column=mincol;last_known_column_point=PT;last_known_column_modified=MODIFF;XSETINT(column,mincol);returncolumn;}DEFUN("current-indentation",Fcurrent_indentation,Scurrent_indentation,0,0,0,"Return the indentation of the current line.\n\This is the horizontal position of the character\n\following any initial whitespace.")(){Lisp_Objectval;XSETFASTINT(val,position_indentation(find_next_newline(PT,-1)));returnval;}position_indentation(pos)registerintpos;{registerintcolumn=0;registerinttab_width=XINT(current_buffer->tab_width);registerunsignedchar*p;registerunsignedchar*stop;unsignedchar*start;intnext_boundary=pos;intceiling=pos;if(tab_width<=0||tab_width>1000)tab_width=8;p=&FETCH_CHAR(pos);/* STOP records the value of P at which we will need to think about the gap, or about invisible text, or about the end of the buffer. */stop=p;/* START records the starting value of P. */start=p;while(1){while(p==stop){intstop_pos;/* If we have updated P, set POS to match. The first time we enter the loop, POS is already right. */if(p!=start)pos=PTR_CHAR_POS(p);/* Consider the various reasons STOP might have been set here. */if(pos==ZV)returncolumn;if(pos==next_boundary)pos=skip_invisible(pos,&next_boundary,ZV,Qnil);if(pos>=ceiling)ceiling=BUFFER_CEILING_OF(pos)+1;/* Compute the next place we need to stop and think, and set STOP accordingly. */stop_pos=min(ceiling,next_boundary);/* The -1 and +1 arrange to point at the first byte of gap (if STOP_POS is the position of the gap) rather than at the data after the gap. */stop=&FETCH_CHAR(stop_pos-1)+1;p=&FETCH_CHAR(pos);}switch(*p++){case' ':column++;break;case'\t':column+=tab_width-column%tab_width;break;default:returncolumn;}}}/* Test whether the line beginning at POS is indented beyond COLUMN. Blank lines are treated as if they had the same indentation as the preceding line. */intindented_beyond_p(pos,column)intpos,column;{while(pos>BEGV&&FETCH_CHAR(pos)=='\n')pos=find_next_newline_no_quit(pos-1,-1);return(position_indentation(pos)>=column);}DEFUN("move-to-column",Fmove_to_column,Smove_to_column,1,2,"p","Move point to column COLUMN in the current line.\n\The column of a character is calculated by adding together the widths\n\as displayed of the previous characters in the line.\n\This function ignores line-continuation;\n\there is no upper limit on the column number a character can have\n\and horizontal scrolling has no effect.\n\\n\If specified column is within a character, point goes after that character.\n\If it's past end of line, point goes to end of line.\n\n\A non-nil second (optional) argument FORCE means, if the line\n\is too short to reach column COLUMN then add spaces/tabs to get there,\n\and if COLUMN is in the middle of a tab character, change it to spaces.\n\\n\The return value is the current column.")(column,force)Lisp_Objectcolumn,force;{registerintpos;registerintcol=current_column();registerintgoal;registerintend;registerinttab_width=XINT(current_buffer->tab_width);registerintctl_arrow=!NILP(current_buffer->ctl_arrow);registerstructLisp_Char_Table*dp=buffer_display_table();Lisp_Objectval;intprev_col;intc;intnext_boundary;if(tab_width<=0||tab_width>1000)tab_width=8;CHECK_NATNUM(column,0);goal=XINT(column);pos=PT;end=ZV;next_boundary=pos;/* If we're starting past the desired column, back up to beginning of line and scan from there. */if(col>goal){end=pos;pos=find_next_newline(pos,-1);col=0;}while(pos<end){while(pos==next_boundary){pos=skip_invisible(pos,&next_boundary,end,Qnil);if(pos>=end)gotoendloop;}/* Test reaching the goal column. We do this after skipping invisible characters, so that we put point before the character on which the cursor will appear. */if(col>=goal)break;c=FETCH_CHAR(pos);if(dp!=0&&VECTORP(DISP_CHAR_VECTOR(dp,c))){col+=XVECTOR(DISP_CHAR_VECTOR(dp,c))->size;pos++;continue;}if(c=='\n')break;if(c=='\r'&&EQ(current_buffer->selective_display,Qt))break;pos++;if(c=='\t'){prev_col=col;col+=tab_width;col=col/tab_width*tab_width;}elseif(ctl_arrow&&(c<040||c==0177))col+=2;elseif(c<040||c>=0177)col+=4;elsecol++;}endloop:SET_PT(pos);/* If a tab char made us overshoot, change it to spaces and scan through it again. */if(!NILP(force)&&col>goal&&c=='\t'&&prev_col<goal){intold_point;del_range(PT-1,PT);Findent_to(make_number(goal),Qnil);old_point=PT;Findent_to(make_number(col),Qnil);SET_PT(old_point);/* Set the last_known... vars consistently. */col=goal;}/* If line ends prematurely, add space to the end. */if(col<goal&&!NILP(force))Findent_to(make_number(col=goal),Qnil);last_known_column=col;last_known_column_point=PT;last_known_column_modified=MODIFF;XSETFASTINT(val,col);returnval;}/* compute_motion: compute buffer posn given screen posn and vice versa */structpositionval_compute_motion;/* Scan the current buffer forward from offset FROM, pretending that this is at line FROMVPOS, column FROMHPOS, until reaching buffer offset TO or line TOVPOS, column TOHPOS (whichever comes first), and return the ending buffer position and screen location. If we can't hit the requested column exactly (because of a tab or other multi-column character), overshoot. DID_MOTION is 1 if FROMHPOS has already accounted for overlay strings at FROM. This is the case if FROMVPOS and FROMVPOS came from an earlier call to compute_motion. The other common case is that FROMHPOS is zero and FROM is a position that "belongs" at column zero, but might be shifted by overlay strings; in this case DID_MOTION should be 0. WIDTH is the number of columns available to display text; compute_motion uses this to handle continuation lines and such. HSCROLL is the number of columns not being displayed at the left margin; this is usually taken from a window's hscroll member. TAB_OFFSET is the number of columns of the first tab that aren't being displayed, perhaps because of a continuation line or something. compute_motion returns a pointer to a struct position. The bufpos member gives the buffer position at the end of the scan, and hpos and vpos give its cartesian location. prevhpos is the column at which the character before bufpos started, and contin is non-zero if we reached the current line by continuing the previous. Note that FROMHPOS and TOHPOS should be expressed in real screen columns, taking HSCROLL and the truncation glyph at the left margin into account. That is, beginning-of-line moves you to the hpos -HSCROLL + (HSCROLL > 0). For example, to find the buffer position of column COL of line LINE of a certain window, pass the window's starting location as FROM and the window's upper-left coordinates as FROMVPOS and FROMHPOS. Pass the buffer's ZV as TO, to limit the scan to the end of the visible section of the buffer, and pass LINE and COL as TOVPOS and TOHPOS. When displaying in window w, a typical formula for WIDTH is: window_width - 1 - (has_vertical_scroll_bars ? FRAME_SCROLL_BAR_COLS (XFRAME (window->frame)) : (window_width + window_left != frame_width)) where window_width is XFASTINT (w->width), window_left is XFASTINT (w->left), has_vertical_scroll_bars is FRAME_HAS_VERTICAL_SCROLL_BARS (XFRAME (WINDOW_FRAME (window))) and frame_width = FRAME_WIDTH (XFRAME (window->frame)) Or you can let window_internal_width do this all for you, and write: window_internal_width (w) - 1 The `-1' accounts for the continuation-line backslashes; the rest accounts for window borders if the window is split horizontally, and the scroll bars if they are turned on. */structposition*compute_motion(from,fromvpos,fromhpos,did_motion,to,tovpos,tohpos,width,hscroll,tab_offset,win)intfrom,fromvpos,fromhpos,to,tovpos,tohpos;intdid_motion;registerintwidth;inthscroll,tab_offset;structwindow*win;{registerinthpos=fromhpos;registerintvpos=fromvpos;registerintpos;registerintc;registerinttab_width=XFASTINT(current_buffer->tab_width);registerintctl_arrow=!NILP(current_buffer->ctl_arrow);registerstructLisp_Char_Table*dp=window_display_table(win);intselective=(INTEGERP(current_buffer->selective_display)?XINT(current_buffer->selective_display):!NILP(current_buffer->selective_display)?-1:0);intprev_vpos=vpos,prev_hpos=0;intselective_rlen=(selective&&dp&&VECTORP(DISP_INVIS_VECTOR(dp))?XVECTOR(DISP_INVIS_VECTOR(dp))->size:0);/* The next location where the `invisible' property changes, or an overlay starts or ends. */intnext_boundary=from;/* For computing runs of characters with similar widths. Invariant: width_run_width is zero, or all the characters from width_run_start to width_run_end have a fixed width of width_run_width. */intwidth_run_start=from;intwidth_run_end=from;intwidth_run_width=0;Lisp_Object*width_table;Lisp_Objectbuffer;/* The next buffer pos where we should consult the width run cache. */intnext_width_run=from;Lisp_Objectwindow;XSETBUFFER(buffer,current_buffer);XSETWINDOW(window,win);width_run_cache_on_off();if(dp==buffer_display_table())width_table=(VECTORP(current_buffer->width_table)?XVECTOR(current_buffer->width_table)->contents:0);else/* If the window has its own display table, we can't use the width run cache, because that's based on the buffer's display table. */width_table=0;if(tab_width<=0||tab_width>1000)tab_width=8;pos=from;while(1){while(pos==next_boundary){/* If the caller says that the screen position came from an earlier call to compute_motion, then we've already accounted for the overlay strings at point. This is only true the first time through, so clear the flag after testing it. */if(!did_motion)/* We need to skip past the overlay strings. Currently those strings must contain single-column printing characters; if we want to relax that restriction, something will have to be changed here. */hpos+=overlay_strings(pos,win,(char**)0);did_motion=0;if(pos>=to)break;/* Advance POS past invisible characters (but not necessarily all that there are here), and store in next_boundary the next position where we need to call skip_invisible. */pos=skip_invisible(pos,&next_boundary,to,window);}/* Handle right margin. */if(hpos>=width&&(hpos>width||(pos<ZV&&FETCH_CHAR(pos)!='\n'))){if(hscroll||(truncate_partial_width_windows&&width+1<FRAME_WIDTH(XFRAME(WINDOW_FRAME(win))))||!NILP(current_buffer->truncate_lines)){/* Truncating: skip to newline. */pos=find_before_next_newline(pos,to,1);hpos=width;/* If we just skipped next_boundary, loop around in the main while and handle it. */if(pos>=next_boundary)next_boundary=pos+1;}else{/* Continuing. */vpos+=hpos/width;tab_offset+=hpos-hpos%width;hpos%=width;}}/* Stop if past the target buffer position or screen position. */if(pos>=to)break;if(vpos>tovpos||(vpos==tovpos&&hpos>=tohpos))break;prev_vpos=vpos;prev_hpos=hpos;/* Consult the width run cache to see if we can avoid inspecting the text character-by-character. */if(current_buffer->width_run_cache&&pos>=next_width_run){intrun_end;intcommon_width=region_cache_forward(current_buffer,current_buffer->width_run_cache,pos,&run_end);/* A width of zero means the character's width varies (like a tab), is meaningless (like a newline), or we just don't want to skip over it for some other reason. */if(common_width!=0){intrun_end_hpos;/* Don't go past the final buffer posn the user requested. */if(run_end>to)run_end=to;run_end_hpos=hpos+(run_end-pos)*common_width;/* Don't go past the final horizontal position the user requested. */if(vpos==tovpos&&run_end_hpos>tohpos){run_end=pos+(tohpos-hpos)/common_width;run_end_hpos=hpos+(run_end-pos)*common_width;}/* Don't go past the margin. */if(run_end_hpos>=width){run_end=pos+(width-hpos)/common_width;run_end_hpos=hpos+(run_end-pos)*common_width;}hpos=run_end_hpos;if(run_end>pos)prev_hpos=hpos-common_width;pos=run_end;}next_width_run=run_end+1;}/* We have to scan the text character-by-character. */else{c=FETCH_CHAR(pos);pos++;/* Perhaps add some info to the width_run_cache. */if(current_buffer->width_run_cache){/* Is this character part of the current run? If so, extend the run. */if(pos-1==width_run_end&&width_table[c]==width_run_width)width_run_end=pos;/* The previous run is over, since this is a character at a different position, or a different width. */else{/* Have we accumulated a run to put in the cache? (Currently, we only cache runs of width == 1). */if(width_run_start<width_run_end&&width_run_width==1)know_region_cache(current_buffer,current_buffer->width_run_cache,width_run_start,width_run_end);/* Start recording a new width run. */width_run_width=width_table[c];width_run_start=pos-1;width_run_end=pos;}}if(dp!=0&&VECTORP(DISP_CHAR_VECTOR(dp,c)))hpos+=XVECTOR(DISP_CHAR_VECTOR(dp,c))->size;elseif(c>=040&&c<0177)hpos++;elseif(c=='\t'){inttem=(hpos+tab_offset+hscroll-(hscroll>0))%tab_width;if(tem<0)tem+=tab_width;hpos+=tab_width-tem;}elseif(c=='\n'){if(selective>0&&indented_beyond_p(pos,selective)){/* Skip any number of invisible lines all at once */dopos=find_before_next_newline(pos,to,1)+1;while(pos<to&&indented_beyond_p(pos,selective));/* Allow for the " ..." that is displayed for them. */if(selective_rlen){hpos+=selective_rlen;if(hpos>=width)hpos=width;}--pos;/* We have skipped the invis text, but not the newline after. */}else{/* A visible line. */vpos++;hpos=0;hpos-=hscroll;/* Count the truncation glyph on column 0 */if(hscroll>0)hpos++;tab_offset=0;}}elseif(c==CR&&selective<0){/* In selective display mode, everything from a ^M to the end of the line is invisible. Stop *before* the real newline. */pos=find_before_next_newline(pos,to,1);/* If we just skipped next_boundary, loop around in the main while and handle it. */if(pos>next_boundary)next_boundary=pos;/* Allow for the " ..." that is displayed for them. */if(selective_rlen){hpos+=selective_rlen;if(hpos>=width)hpos=width;}}elsehpos+=(ctl_arrow&&c<0200)?2:4;}}/* Remember any final width run in the cache. */if(current_buffer->width_run_cache&&width_run_width==1&&width_run_start<width_run_end)know_region_cache(current_buffer,current_buffer->width_run_cache,width_run_start,width_run_end);val_compute_motion.bufpos=pos;val_compute_motion.hpos=hpos;val_compute_motion.vpos=vpos;val_compute_motion.prevhpos=prev_hpos;/* We alalways handle all of them here; none of them remain to do. */val_compute_motion.ovstring_chars_done=0;/* Nonzero if have just continued a line */val_compute_motion.contin=(pos!=from&&(val_compute_motion.vpos!=prev_vpos)&&c!='\n');return&val_compute_motion;}#if 0 /* The doc string is too long for some compilers, but make-docfile can find it in this comment. */DEFUN ("compute-motion", Ffoo, Sfoo, 7, 7, 0, "Scan through the current buffer, calculating screen position.\n\Scan the current buffer forward from offset FROM,\n\assuming it is at position FROMPOS--a cons of the form (HPOS . VPOS)--\n\to position TO or position TOPOS--another cons of the form (HPOS . VPOS)--\n\and return the ending buffer position and screen location.\n\\n\There are three additional arguments:\n\\n\WIDTH is the number of columns available to display text;\n\this affects handling of continuation lines.\n\This is usually the value returned by `window-width', less one (to allow\n\for the continuation glyph).\n\\n\OFFSETS is either nil or a cons cell (HSCROLL . TAB-OFFSET).\n\HSCROLL is the number of columns not being displayed at the left\n\margin; this is usually taken from a window's hscroll member.\n\TAB-OFFSET is the number of columns of the first tab that aren't\n\being displayed, perhaps because the line was continued within it.\n\If OFFSETS is nil, HSCROLL and TAB-OFFSET are assumed to be zero.\n\\n\WINDOW is the window to operate on. It is used to choose the display table;\n\if it is showing the current buffer, it is used also for\n\deciding which overlay properties apply.\n\Note that `compute-motion' always operates on the current buffer.\n\\n\The value is a list of five elements:\n\ (POS HPOS VPOS PREVHPOS CONTIN)\n\POS is the buffer position where the scan stopped.\n\VPOS is the vertical position where the scan stopped.\n\HPOS is the horizontal position where the scan stopped.\n\\n\PREVHPOS is the horizontal position one character back from POS.\n\CONTIN is t if a line was continued after (or within) the previous character.\n\\n\For example, to find the buffer position of column COL of line LINE\n\of a certain window, pass the window's starting location as FROM\n\and the window's upper-left coordinates as FROMPOS.\n\Pass the buffer's (point-max) as TO, to limit the scan to the end of the\n\visible section of the buffer, and pass LINE and COL as TOPOS.") (from, frompos, to, topos, width, offsets, window)#endifDEFUN("compute-motion",Fcompute_motion,Scompute_motion,7,7,0,0)(from,frompos,to,topos,width,offsets,window)Lisp_Objectfrom,frompos,to,topos;Lisp_Objectwidth,offsets,window;{Lisp_Objectbufpos,hpos,vpos,prevhpos,contin;structposition*pos;inthscroll,tab_offset;CHECK_NUMBER_COERCE_MARKER(from,0);CHECK_CONS(frompos,0);CHECK_NUMBER(XCONS(frompos)->car,0);CHECK_NUMBER(XCONS(frompos)->cdr,0);CHECK_NUMBER_COERCE_MARKER(to,0);CHECK_CONS(topos,0);CHECK_NUMBER(XCONS(topos)->car,0);CHECK_NUMBER(XCONS(topos)->cdr,0);CHECK_NUMBER(width,0);if(!NILP(offsets)){CHECK_CONS(offsets,0);CHECK_NUMBER(XCONS(offsets)->car,0);CHECK_NUMBER(XCONS(offsets)->cdr,0);hscroll=XINT(XCONS(offsets)->car);tab_offset=XINT(XCONS(offsets)->cdr);}elsehscroll=tab_offset=0;if(NILP(window))window=Fselected_window();elseCHECK_LIVE_WINDOW(window,0);pos=compute_motion(XINT(from),XINT(XCONS(frompos)->cdr),XINT(XCONS(frompos)->car),0,XINT(to),XINT(XCONS(topos)->cdr),XINT(XCONS(topos)->car),XINT(width),hscroll,tab_offset,XWINDOW(window));XSETFASTINT(bufpos,pos->bufpos);XSETINT(hpos,pos->hpos);XSETINT(vpos,pos->vpos);XSETINT(prevhpos,pos->prevhpos);returnFcons(bufpos,Fcons(hpos,Fcons(vpos,Fcons(prevhpos,Fcons(pos->contin?Qt:Qnil,Qnil)))));}/* Return the column of position POS in window W's buffer. The result is rounded down to a multiple of the internal width of W. This is the amount of indentation of position POS that is not visible in its horizontal position in the window. */intpos_tab_offset(w,pos)structwindow*w;registerintpos;{intopoint=PT;intcol;intwidth=window_internal_width(w)-1;if(pos==BEGV||FETCH_CHAR(pos-1)=='\n')return0;TEMP_SET_PT(pos);col=current_column();TEMP_SET_PT(opoint);returncol-(col%width);}/* Fvertical_motion and vmotion */structpositionval_vmotion;structposition*vmotion(from,vtarget,w)registerintfrom,vtarget;structwindow*w;{intwidth=window_internal_width(w)-1;inthscroll=XINT(w->hscroll);structpositionpos;/* vpos is cumulative vertical position, changed as from is changed */registerintvpos=0;Lisp_Objectprevline;registerintfirst;intlmargin=hscroll>0?1-hscroll:0;intselective=(INTEGERP(current_buffer->selective_display)?XINT(current_buffer->selective_display):!NILP(current_buffer->selective_display)?-1:0);Lisp_Objectwindow;intstart_hpos=0;intdid_motion;XSETWINDOW(window,w);/* The omission of the clause && marker_position (w->start) == BEG here is deliberate; I think we want to measure from the prompt position even if the minibuffer window has scrolled. */if(EQ(window,minibuf_window)){if(minibuf_prompt_width==0&&STRINGP(minibuf_prompt))minibuf_prompt_width=string_display_width(minibuf_prompt,Qnil,Qnil);start_hpos=minibuf_prompt_width;}if(vpos>=vtarget){/* To move upward, go a line at a time until we have gone at least far enough */first=1;while((vpos>vtarget||first)&&from>BEGV){Lisp_Objectpropval;XSETFASTINT(prevline,find_next_newline_no_quit(from-1,-1));while(XFASTINT(prevline)>BEGV&&((selective>0&&indented_beyond_p(XFASTINT(prevline),selective))#ifdef USE_TEXT_PROPERTIES/* watch out for newlines with `invisible' property */||(propval=Fget_char_property(prevline,Qinvisible,window),TEXT_PROP_MEANS_INVISIBLE(propval))#endif))XSETFASTINT(prevline,find_next_newline_no_quit(XFASTINT(prevline)-1,-1));pos=*compute_motion(XFASTINT(prevline),0,lmargin+(XFASTINT(prevline)==BEG?start_hpos:0),0,from,1<<(BITS_PER_INT-2),0,width,hscroll,0,w);vpos-=pos.vpos;first=0;from=XFASTINT(prevline);}/* If we made exactly the desired vertical distance, or if we hit beginning of buffer, return point found */if(vpos>=vtarget){val_vmotion.bufpos=from;val_vmotion.vpos=vpos;val_vmotion.hpos=lmargin;val_vmotion.contin=0;val_vmotion.prevhpos=0;val_vmotion.ovstring_chars_done=0;return&val_vmotion;}/* Otherwise find the correct spot by moving down */}/* Moving downward is simple, but must calculate from beg of line to determine hpos of starting point */if(from>BEGV&&FETCH_CHAR(from-1)!='\n'){Lisp_Objectpropval;XSETFASTINT(prevline,find_next_newline_no_quit(from,-1));while(XFASTINT(prevline)>BEGV&&((selective>0&&indented_beyond_p(XFASTINT(prevline),selective))#ifdef USE_TEXT_PROPERTIES/* watch out for newlines with `invisible' property */||(propval=Fget_char_property(prevline,Qinvisible,window),TEXT_PROP_MEANS_INVISIBLE(propval))#endif))XSETFASTINT(prevline,find_next_newline_no_quit(XFASTINT(prevline)-1,-1));pos=*compute_motion(XFASTINT(prevline),0,lmargin+(XFASTINT(prevline)==BEG?start_hpos:0),0,from,1<<(BITS_PER_INT-2),0,width,hscroll,0,w);did_motion=1;}else{pos.hpos=lmargin+(from==BEG?start_hpos:0);pos.vpos=0;did_motion=0;}returncompute_motion(from,vpos,pos.hpos,did_motion,ZV,vtarget,-(1<<(BITS_PER_INT-2)),width,hscroll,pos.vpos*width,w);}DEFUN("vertical-motion",Fvertical_motion,Svertical_motion,1,2,0,"Move point to start of the screen line LINES lines down.\n\If LINES is negative, this means moving up.\n\\n\This function is an ordinary cursor motion function\n\which calculates the new position based on how text would be displayed.\n\The new position may be the start of a line,\n\or just the start of a continuation line.\n\The function returns number of screen lines moved over;\n\that usually equals LINES, but may be closer to zero\n\if beginning or end of buffer was reached.\n\\n\The optional second argument WINDOW specifies the window to use for\n\parameters such as width, horizontal scrolling, and so on.\n\The default is to use the selected window's parameters.\n\\n\`vertical-motion' always uses the current buffer,\n\regardless of which buffer is displayed in WINDOW.\n\This is consistent with other cursor motion functions\n\and makes it possible to use `vertical-motion' in any buffer,\n\whether or not it is currently displayed in some window.")(lines,window)Lisp_Objectlines,window;{structpositionpos;CHECK_NUMBER(lines,0);if(!NILP(window))CHECK_WINDOW(window,0);elsewindow=selected_window;pos=*vmotion(PT,(int)XINT(lines),XWINDOW(window));SET_PT(pos.bufpos);returnmake_number(pos.vpos);}/* file's initialization. */syms_of_indent(){DEFVAR_BOOL("indent-tabs-mode",&indent_tabs_mode,"*Indentation can insert tabs if this is non-nil.\n\Setting this variable automatically makes it local to the current buffer.");indent_tabs_mode=1;defsubr(&Scurrent_indentation);defsubr(&Sindent_to);defsubr(&Scurrent_column);defsubr(&Smove_to_column);defsubr(&Svertical_motion);defsubr(&Scompute_motion);}